JP2774507B2 - Shift lock device for automatic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shift lock device for an automatic transmission having a stop range and a travel range.

(Prior Art) In recent years, for example, as disclosed in Japanese Patent Application Laid-Open No. 62-279146, when shifting an automatic transmission from a stop range to a travel range, if the brake operation is not performed, the shift operation is performed. A so-called shift lock device has been developed to prevent the shift from being performed.

Thus, in the shift lock device disclosed in the above publication, a brake lamp switch is used to detect the presence or absence of a brake operation, and the brake lamp is turned on and off.
The shift operation of the transmission is locked or permitted by determining the presence or absence of braking from the off operation.

(Problems to be Solved by the Invention) By the way, the brake lamp switch is intended to be turned on even when the brake pedal is slightly depressed and sufficient braking force is not generated in the brake. As disclosed in the above publication, when the presence or absence of a brake operation is determined from the on / off operation of the brake lamp switch, even when the brake pedal is not sufficiently pressed and the braking force has not yet been reliably obtained, the automatic transmission of the automatic transmission is controlled. The shift operation becomes possible, so that it is difficult to achieve the intended purpose of the shift lock device.

The present invention has been developed in view of the above circumstances, and the purpose is to shift the automatic transmission to the stop range by a hydraulic circuit using the line pressure and the brake fluid pressure of the hydraulically operated automatic transmission. In the case where
Provided is a shift lock device for an automatic transmission in which shifting of the automatic transmission is disabled when a brake operation is not performed, and the shift operation of the automatic transmission can be performed only when the vehicle is securely braked with the brake operation. To be.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a hydraulically operated automatic transmission having a stop range and a traveling range, in which a hydraulic pressure is adjusted in accordance with a switching operation to each range. Fluctuate,
A range detection hydraulic circuit for inputting the switching hydraulic pressure as a detection signal to detect a range during shifting, and a setting for inputting brake fluid pressure as a detection signal so that the brake fluid pressure can obtain a predetermined braking force. Based on the detection results of the braking detection hydraulic circuit for detecting whether or not the value is equal to or more than a value, a lock hydraulic circuit for locking an inner lever of the automatic transmission interlocked with a shift lever, and the detection hydraulic circuits. When the transmission is shifted to a stop range and the brake fluid pressure is below a set value,
A line pressure is supplied to the lock hydraulic circuit to disable shifting of the transmission, and when the transmission is shifted to a travel range or a stop range, and the brake fluid is When the pressure is larger than the set value, the supply of the line pressure to the lock hydraulic circuit is blocked,
And a control hydraulic circuit that releases the hydraulic pressure of the lock hydraulic circuit to the drain to enable shifting of the transmission.

(Action) According to the present invention, when the automatic transmission is shifted to the stop range, if the brake fluid pressure detected by the brake detection hydraulic circuit is a value that cannot reliably brake the vehicle, The line pressure is supplied to the lock hydraulic circuit by the control hydraulic circuit, and the shift operation of the transmission is locked to prevent the vehicle from suddenly starting suddenly. Only when the control hydraulic circuit reaches a value at which the brake can be reliably braked, the supply of line pressure to the lock hydraulic circuit is prevented by the control hydraulic circuit, and the hydraulic pressure of the lock hydraulic circuit is released to the drain. The shift operation of the transmission becomes possible.

(Embodiment) Hereinafter, a shift lock device for an automatic transmission according to the present invention will be described with reference to embodiments shown in the drawings.

The shift lock device for an automatic transmission shown in FIG. 1 is used to shift-lock an automatic transmission that can be shifted under a predetermined condition by a manual valve switching operation accompanying a shift operation of a shift lever. The transmission includes a torque converter and a planetary gear mechanism having an engagement element composed of a plurality of clutches and the like, and the engagement element is operated via an actuator including a cylinder and a hydraulically-operated piston, thereby shifting. It is of a hydraulically operated type.

The above automatic transmission has a parking range (P) and a neutral range (N) as stop ranges, and a drive range (D), a second range (II) and a low range (L) as running ranges. ) And a reverse range (R), and the shift pattern is (P)-(R)-(N)-(D)-(II)-(L) as is known.

The shift lock device of the automatic transmission described above utilizes a line pressure which is a control oil pressure of the automatic transmission, a governor pressure generated in a governor of the automatic transmission, and a brake fluid pressure of the brake device (1). Basically, the brake fluid pressure generated in the brake device (1) is inputted as a detection signal, and whether or not the brake fluid pressure is equal to or more than a set value capable of obtaining a predetermined braking force is determined. (2), a drive range (D), a second range (II), and a low range (L) of the traveling range of the automatic transmission.
Range detection hydraulic circuit (3) for detecting the shift range of the automatic transmission by inputting the switching operation hydraulic pressure to the automatic transmission as a detection signal, and a governor hydraulic pressure for detecting the governor hydraulic pressure generated in the governor of the automatic transmission. A detection hydraulic circuit (4), a lock hydraulic circuit (5) that operates by line pressure and locks an inner lever of the automatic transmission that is interlocked with a shift lever, and a brake that includes the range detection hydraulic circuit (3). Based on the detection results by the detection hydraulic circuit (2) and the governor hydraulic detection hydraulic circuit (4), when the transmission is shifted to the stop range and the governor hydraulic pressure and the brake hydraulic pressure are below the set values. A line pressure is supplied to the lock hydraulic circuit (5) to lock the lock hydraulic circuit (5), thereby disabling shifting of the transmission. Preventing the supply of line pressure to the lock hydraulic circuit (5) when shifting to the line range or when shifting to the stop range and when the brake fluid pressure is greater than a set value; A control hydraulic circuit (6) that releases the hydraulic pressure of the lock hydraulic circuit (5) to the drain, releases the lock hydraulic circuit (5), and allows the transmission to shift. .

The brake device (1) has a known structure, and has a master cylinder (12) interlockedly connected to a brake pedal (11), and a hydraulic pipeline (13) extending from the master cylinder (12). Connected to a wheel cylinder (15) incorporated in a wheel (14), and by depressing the brake pedal (11), the brake fluid pressure pressurized by a piston of the master cylinder (12) is applied to the wheel cylinder (15).
To brake the wheels (14).

The braking detection hydraulic circuit (2) inputs a brake fluid pressure generated in the master cylinder (12) and determines whether the brake fluid pressure is equal to or higher than a set value capable of obtaining a predetermined braking force. More specifically, as shown in FIG. 2, a valve body in which a ball valve (22a) is mounted on a back side in a valve chamber (21a) of a valve body (21). And a brake fluid pressure supply port (23) for connecting a brake fluid pressure supply passage (16) to the valve chamber (21a) on the working surface side of the valve element (22). )
A control port (24) of control hydraulic pressure for connecting a first control oil passage (L1) on a back side of the valve body (22);
A drain port (25) for connecting a drain passage (L2) extending to the oil pan is provided, and the control port (24) is opened and closed via the ball valve (22a) by the operation of the valve element (22). On the other hand, on the back side of the valve element (22) in the valve chamber (21a), a return spring (26) for moving the valve element (22) in the opening direction (right direction in FIG. 2) is provided. It is interposed.

The above-described braking detection hydraulic circuit (2) has a value (set value) at which the brake fluid pressure generated in the master cylinder (12) can reliably brake the wheels (14) by depressing the brake pedal (11). Above), the valve body (22) is moved leftward in FIG. 2 against the return spring (26), and the control port (24) is moved by the ball valve (22a). When the brake pedal (11) is not depressed, or is depressed, the master cylinder (12) is closed.
When the brake fluid pressure generated in the step (c) is a value (below the set value) at which the wheel (14) cannot be reliably braked, the return spring (26) acts against the brake fluid pressure by the spring force of the return spring (26). When the valve element (22) is moved back, the control port (24) communicates with the drain port (25),
The control oil pressure in the control oil passage (L1) is released to the oil pan.

Thus, a line pressure for operating the automatic transmission is introduced into the first control oil passage (L1), and the line pressure is used as a control oil pressure.

As shown in FIGS. 1 and 6, the range detection hydraulic circuit (3) includes a first input port (31) for introducing a switching hydraulic pressure to a traveling range of the automatic transmission, and the first control oil passage. Second input port (32) for introducing the control oil pressure in (L1)
The output port (33) is provided in a valve chamber (35) of a valve element (34) having a hydraulic pressure input to the first and second input ports (31) and (32). The check ball (36) that opens and closes) is inserted.

In the embodiment shown in the figure, the first input port (31) is provided with a switching of an engagement element that performs an engagement operation regardless of switching to any of the drive range (D), the second range (II), and the low range (L). Working hydraulic pressure is introduced.

The above-described range detection hydraulic circuit (3) is characterized in that the automatic transmission has a drive range (D) and a second range (I
When the mode is switched to either I) or the low range (L), the valve chamber (35) is switched through the first input port (31).
The check ball (36) is moved rightward in FIG. 6 by the working oil pressure introduced into the inside to close the second input port (32) and output the working oil pressure from the output port (33). You do it.

When the automatic transmission is switched to one of the parking range (P), the neutral range (N), and the reverse range (R), no hydraulic pressure is generated at the first input port (31). Therefore, as described above, only when the control port (24) of the braking detection hydraulic circuit (2) is closed by the depression operation of the brake pedal (11), the control oil pressure in the control oil passage (L1) is reduced. Introduced into the valve chamber (35) via the second input port (32), the check ball (36) is moved to the left in FIG. 6, and the first input port (31) is closed. The control oil pressure is output from the first output port (33). In contrast, the control port (24) of the braking detection oil pressure circuit (2) is opened, and the control oil passage (L1) is opened. Is the drain oil passage (L2) When it is opened, because the control pressure of the first control oil passage (L1) is opened to the drain pan, said the first output port (33) so that the control oil pressure is not output.

Next, as shown in FIGS. 3 and 4, the lock hydraulic circuit (5) includes a valve case (51) having a valve chamber (51a).
A through hole (52) extending coaxially with the valve chamber (51a) is formed in the through hole (52) and the valve chamber (51a). And a piston (54) sliding in the valve chamber (51a) on the small-diameter shaft portion (53a) of the lock body (53). ) And insert the piston (54)
The step (53c) of the large-diameter shaft (53b) and the small-diameter shaft (53b)
The automatic transmission can be freely moved in the working chamber (56) provided on the working surface side of the piston (54) while allowing free movement in the axial direction only between the stop ring (55) fitted on the free end side of (a). The line pressure for performing the operation is introduced.

A first spring (57) is interposed between the back surface of the piston (54) in the valve chamber (51a) and the step (53c) of the large-diameter shaft portion (53b) in the lock body (53). A second spring having a stronger spring force than the first spring (57) between the back surface of the piston (54) and the valve case (51).
The spring (58) is interposed.

As shown in FIG. 4, the manual valve (7) of the automatic transmission which is disabled by the lock hydraulic circuit (5) is an inner lever that swings with a manual operation of a shift lever (not shown). (70) and connecting pin (70a)
And has a known structure in which the inner lever (70) is operated in the axial direction by swinging of the inner lever (70). In the embodiment shown in FIG. A plate (71) is integrally formed, and the lock hydraulic circuit (5) is provided on one side of the lock plate (71).
On the other hand, in the lock plate (71),
When the shift lever is operated in the parking range (P) and the neutral range (N), the lock body (53) is fitted to a position facing the end face of the lock body (53) of the lock hydraulic circuit (5). First and second fitting holes (72) (73)
And the first or second lock body (53)
The fitting of the inner lever (70) by fitting into the fitting holes (72) and (73), in other words, the manual valve (7)
The operation of is prevented.

When the hydraulic pressure is introduced into the working chamber (56), for example, when the automatic transmission is shifted to the neutral range (N), the lock hydraulic circuit (5) The piston (54) moves forward (downward in FIG. 3) against the second spring (58). With the forward movement of the piston (54), the lock body ( 53) also moves forward, and the end of the large-diameter shaft portion (53b) of the lock body (53) projects from the valve case (51) and fits in the second fitting hole (73). . At this time, if the second fitting hole (73) is not located at a position facing the end face of the lock body (53), the end face of the lock body (53) is connected to the lock plate (71). ), It is impossible to move forward by contacting the side surface, but only the piston (54) moves forward, compresses the first spring (57), and operates the inner lever ( 70), the second fitting hole (7
3) when the lock body (53) faces the end face of the lock body (53), the lock body (53) moves forward by the spring force of the first spring (57), and the large-diameter shaft portion (53b) moves to the It fits into the two fitting holes (73).

On the other hand, the governor oil pressure detection oil pressure circuit (4) is incorporated in a control oil pressure circuit (6) for locking the lock oil pressure circuit (5). Next, the control oil pressure circuit (6) will be described. I do.

As shown in FIGS. 5 and 6, the control hydraulic circuit (6) includes a housing hole (61a) formed in the valve body (61).
A three-land type spool (62) having first, second, and third lands (62a), (62b), and (62c) therein, and outside the first land (62a) in the spool (62). A spring chamber (S2) is provided on the outside of the third land (63c) of the spool (62), and the spool (62) is mounted on the spring chamber (S2). Coil spring (64) for urging the working chamber (S1) side
Is interposed.

The lands (62a), (62b) and (62c) have the same diameter as the second and third lands (62b) and (62c).
The land (62a) has a smaller diameter than the second land (62b).

A governor oil passage (41) for guiding a governor oil pressure generated in a governor (G) of the transmission is connected to the working chamber (S1), and the working chamber (S1) is connected to the spool (62). The first land (62a) and the second land (62a) constitute the governor oil pressure detection hydraulic circuit (4).
A second control oil passage (L) extending from the output port (33) of the range detection hydraulic circuit (3) between the land and the land (62b).
3), and a supply oil between the second land (62b) and the third land (62c) for introducing line pressure into the working chamber (56) of the lock hydraulic circuit (5). Road (L4)
A primary passage (L4-1) and a secondary passage (L4-2) are connected to each other, and a drain oil passage (L5) opened to an oil pan is connected to the spring chamber (S2). .

In the embodiment shown in the figure, an accumulator (8) for temporarily storing hydraulic oil introduced into the supply oil passage (L4) is provided in the valve body (61). Specifically, as shown in FIG. 5, the valve body (61) is provided with the second and the second holes in the receiving hole (61a).
An accumulator chamber (81) communicating between the third lands (62b) and (62c) is formed, and the accumulator chamber (81) has an accumulator piston (82) and a return spring (83).
And the interior is decorated.

When the lock hydraulic circuit (5) performs the locking operation, the accumulator (8) is actuated by the pressure of the operating oil introduced from the primary passage (L4-1) of the supply oil passage (L4). Moving the accumulator piston (82) forward against the return spring (83) to temporarily store the hydraulic oil in the accumulator chamber (81);
This is for causing a time lag in the lock operation of the lock hydraulic circuit (5).

In the control hydraulic circuit (6), the spring force of the coil spring (64) provided in the spring chamber (S2) is determined by the governor oil pressure introduced into the working chamber (S1) at a speed of 15 / h.
15km / h, stronger than the hydraulic pressure generated when traveling below km
The value is set to a value weaker than the hydraulic pressure generated during traveling as described above. Therefore, when the vehicle is traveling at a speed of 15 km / h or more, the spool (62) is always attached to the coil spring (64). The second land (62)
b) the primary passage (L4-1) of the supply oil passage (L4)
And the secondary side passageway (L4-2) is disconnected, and the secondary side passageway (L4-2) and the accumulator chamber (81) are opened to the drain oil passageway (L5).

 Note that (O) in the figure indicates an orifice.

Next, the operation of the shift lock device for an automatic transmission having the above configuration will be described.

First, when the shift lever of the automatic transmission is shifted to either the parking range (P) or the neutral range (N) at the time of starting, the first input port of the range detection hydraulic circuit (3). No operating oil pressure is introduced to (31).

Do not step on the brake pedal in such a state,
Alternatively, when the brake fluid pressure generated in the master cylinder (12) even when depressed is a value (below a set value) at which the wheels (14) cannot be reliably braked, the valve body of the brake detection hydraulic circuit (2) (22) moves rightward in FIG. 2 by the spring force of the return spring (26), and the control port (24) communicates with the drain port (25). The control oil pressure of the road (L1) is released to the oil pan, and therefore, between the first and second lands (62a) and (62b) of the spool (62) in the control oil pressure circuit (6), the operating oil pressure and the control oil pressure are controlled. Neither is introduced,
Since the governor oil pressure introduced into the working chamber (S1) is weaker than the spring force of the coil spring (64) at the time of starting, the spool (62) is, as shown in FIG. It is located at a position where it has been moved back by the spring force of the coil spring (64).

When the spool (62) is located at the return position, the spool (62) operates from the primary passage (L4-1) of the supply oil passage (L4) to the secondary passage (L4-2) and the accumulator chamber (81). Oil is supplied, and the pressure of the hydraulic oil causes the accumulator piston (82) to return to the return spring (8).
It moves forward against 3).

Then, after a predetermined amount of the hydraulic oil remains in the accumulator chamber (81), operating hydraulic pressure is supplied to the operating chamber (56) of the lock hydraulic circuit (5), and the piston (54) and the first spring (57) through the lock body (5
3) moves forward, and the large-diameter shaft portion (53
If the end of b) is a parking range, a first fitting hole (72) formed in the lock plate (71) of the inner lever (70) is inserted into a second fitting hole (72) if the end is a neutral range. ) To fit the inner lever (70)
The automatic transmission cannot be shifted from the stop range to the drive range if the brake operation is not performed reliably at the time of starting, which causes the vehicle to be inadvertent It is possible to prevent the vehicle from starting.

In this state, the depressing operation of the brake pedal (11) is performed, and the brake fluid pressure generated in the master cylinder (12) is set to a value (above a set value) capable of reliably braking the wheels (14). Then, the valve element (22) of the braking detection hydraulic circuit (2) moves forward in the leftward direction in FIG. 2 against the return spring (26) by the action of the brake fluid pressure, and the ball valve (22a ), The control port (24) is closed, and a control oil pressure is generated in the first control oil passage (L1).

The control oil pressure generated in the first control oil passage (L1) is introduced into the valve chamber (35) through the second input port (32) of the range detection hydraulic circuit (3), and the check ball (36), the check ball (36) is moved to the left in FIG. 6 to close the first input port (31), and the second input port (32) and the output port (33).
The control hydraulic pressure is accordingly transmitted through the output port (33) and the second control oil passage (L3) to the first and second lands (62) of the spool (62) in the control hydraulic circuit (6). 62a) and (62b), the first and second lands (62
a) The spool (62) is moved rightward in FIG. 5 against the coil spring (64) by the control oil pressure acting on the area difference between (62b).

Then, with the forward movement of the spool (62), the second land (62b) allows the primary side passage (L) of the supply oil passage (L4) to move.
The communication between 4-1) and the secondary passage (L4-2) is interrupted, and the secondary passage (L4-2) and the accumulator chamber (81) communicate with the drain oil passage (L5). Thus, the control oil pressure in the working chamber (56) of the lock hydraulic circuit (5) and the accumulator chamber (81) is released to the drain oil passage (L5), whereby the lock body (5) of the lock hydraulic circuit (5) is released. 53) is returned by the spring force of the second spool ring (58), and the large-diameter shaft portion (53b) is moved in the first fitting groove (72) or the second fitting hole (52) of the lock brake (71). 73) to release the lock of the inner lever (70),
Therefore, thereafter, it is possible to shift the automatic transmission to an arbitrary range.

By the way, for example, during high-speed running, the governor oil pressure introduced into the working chamber (S1) is higher than the spring force of the coil spring (64) in the spring chamber (S2),
Since the spool (62) is held at the forward position by the action of the governor oil pressure, as described above, the inner lever (70) is not locked. When the drive range (D) is erroneously shifted to the neutral range (N), the automatic transmission is immediately returned to, for example, the drive range (D) without performing the brake operation each time as in the case of starting. Can be done.

On the other hand, when the automatic transmission is shifted to any one of the drive range (D), the second range (II), and the low range (L), the first input port (31) of the range detection hydraulic circuit (3). ) Is introduced into the valve chamber (35), and the first input port (32) and the output port (33) are moved by the right movement of the check ball (36) in FIG. And the operating oil pressure is applied to the first and second lands (62a) (62a) of the spool (62) in the control oil pressure circuit (6) via the output port (33) and the second control oil passage (L3). 62b), the first and second lands (62
a) The spool (62) moves rightward in FIG. 5 against the coil spring (64) by the operating oil pressure acting on the area difference of (62b).

Then, with the forward movement of the spool (62), the second land (62b) allows the primary side passage (L) of the supply oil passage (L4) to move.
The communication between 4-1) and the secondary passage (L4-2) is interrupted, and the secondary passage (L4-2) and the accumulator chamber (81) are opened to the drain oil passage (L5). Therefore, no operating hydraulic pressure is introduced into the working chamber (56) of the lock hydraulic circuit (5), and the lock hydraulic circuit (5) is kept in an unlocked state.

Therefore, when the automatic transmission is in one of the drive range (D), the second range (II), and the low range (L), the automatic transmission can be freely shifted to another range.

By the way, in the above embodiment, when the automatic transmission is shifted to the reverse range (R), similarly to the case where the automatic transmission is shifted to the parking range, the brake cannot reliably brake the wheel (14). Less than or equal to)
When the operating oil pressure is introduced into the working chamber (56) of the lock hydraulic circuit (5), the lock body (53) moves forward, but the end surface of the lock body (53) is set to the side surface of the lock plate (71). , The inner lever (70) is not locked, so that the shift from the reverse range (R) to another range can be freely performed.

On the other hand, the automatic transmission is switched from the drive range (D) to the reverse range (R) and further from the reverse range (R) to the drive range (D) when the vehicle is parked in the garage or in parallel parking, so that the forward and reverse movements are performed. In such a case, each time the vehicle passes through the neutral range (N), the sleeve (62) of the control hydraulic circuit (6) returns once each time the vehicle passes through the neutral range (N). , The primary passage (L4−) of the supply oil passage (L4).
1) communicates with the secondary side passage (L4-2).

However, as described above, even if the primary passage (L4-1) of the supply oil passage (L4) is in primary communication with the secondary passage (L4-2), the lock by the operation of the accumulator (8) is maintained. Since the automatic transmission is switched from the neutral range to another range before the working oil pressure acts on the working chamber (56) of the hydraulic circuit (5), the neutral range (N)
It is not necessary to operate the brake every time the vehicle passes, so that the vehicle can be smoothly parked in the garage or in parallel parking.

(Effects of the Invention) As described above, the present invention provides a hydraulically operated automatic transmission having a stop range and a traveling range, in which the hydraulic pressure is varied in accordance with the switching operation of each range, and the switching operation hydraulic pressure is detected by a detection signal. And a range detection hydraulic circuit for detecting the range being shifted and inputting the brake fluid pressure as a detection signal to determine whether the brake fluid pressure is equal to or greater than a set value capable of obtaining a predetermined braking force. A hydraulic circuit for detecting braking, a lock hydraulic circuit for locking an inner lever of the automatic transmission that is interlocked with a shift lever,
When the transmission is shifted to a stop range and the brake fluid pressure is equal to or less than a set value, a line pressure is supplied to the lock hydraulic circuit based on a detection result by each of the detection hydraulic circuits. The shifting of the transmission is disabled, and when the transmission is shifted to the travel range, or when the transmission is shifted to the stop range and the brake fluid pressure is greater than a set value, the line pressure is locked. A control hydraulic circuit that blocks supply to the hydraulic circuit and releases the hydraulic pressure of the lock hydraulic circuit to the drain to enable shifting of the transmission. If the brake fluid pressure detected by the brake detection hydraulic circuit is a value at which the vehicle cannot be reliably braked when the vehicle shifts to the travel range and starts, the control oil By the circuit, the line pressure is supplied to the lock hydraulic circuit, the shift operation of the transmission is locked, and the control hydraulic circuit is not actuated until the brake hydraulic pressure becomes a value that can reliably brake the vehicle. Since the supply of the line pressure to the lock hydraulic circuit is prevented, and the hydraulic pressure of the lock hydraulic circuit is released to the drain, the shift operation of the transmission becomes possible. Can be reliably prevented.

In addition, since the shift lock device is configured using the hydraulic circuit, the shift lock device can be configured at a low cost, and the shift lock device can be arranged in the housing of the automatic transmission. Since the circuit is used, the reliability is improved without problems such as a contact failure which is likely to occur when performing electromagnetic control.

[Brief description of the drawings]

1 is a schematic explanatory view showing one embodiment of a lock device for an automatic transmission according to the present invention, FIG. 2 is a cross-sectional view of a brake detection hydraulic circuit, FIG. 3 is a cross-sectional view of a main part of the lock hydraulic circuit, 4 is a schematic perspective view of a lock hydraulic circuit, FIG. 5 is a sectional view of a control hydraulic circuit, and FIG. 6 is a sectional view taken along line VI-VI of FIG. (2) ... Hydraulic circuit for braking detection (3) ... Hydraulic circuit for range detection (5) ... Lock hydraulic circuit (6) ... Control hydraulic circuit

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 61/16 F16H 63/34

Claims (1)

(57) [Claims] 1. A hydraulically operated automatic transmission having a stop range and a travel range, wherein the hydraulic pressure is changed in accordance with a switching operation to each of the ranges.
A range detection hydraulic circuit for inputting the switching operation oil pressure as a detection signal and detecting a range during shifting, and a setting for inputting brake fluid pressure as a detection signal so that the brake fluid pressure can obtain a predetermined braking force. A braking hydraulic pressure circuit for detecting whether the value is equal to or greater than a value, a lock hydraulic circuit for locking an inner lever of the automatic transmission interlocked with a shift lever, and a detection result by each of the detection hydraulic circuits. When the transmission is shifted to a stop range and the brake fluid pressure is equal to or less than a set value, a line pressure is supplied to the lock hydraulic circuit to disable the shift of the transmission, and When the transmission is shifted to the drive range or to the stop range and the brake fluid pressure is greater than the set value, the line pressure A control hydraulic circuit for preventing supply to the lock hydraulic circuit and releasing hydraulic pressure of the lock hydraulic circuit to a drain to enable shifting of the transmission. Shift lock device.